st: weights with Gaussian Kernel in lpoly, Stata 11

In a nonparametric regression using the lpoly command, I would like to
put different weights on observations.

However, when I want to use the Gaussian Kernel, I get the following error:
cross(): 3200 conformability error
_lpoly_work(): - function returned error
<istmt>: - function returned error
For all the other kernels, the option [aw] runs.

Could you tell me if there is something special with the Gaussian kernel
or if it is a bug in the lpoly ?